Not Applicable.
The valved bottle of this invention is described as being filled with a mixture of nitrogen as a carrier gas and ethanol, the mixture being used to standardize or calibrate a breath alcohol testing device, but its utility is not confined thereto. In calibrating breath alcohol determining devices, it is essential that a calibrating gas be uniform and of exactly known alcohol content. The temperature of the ambient air around the cylinder is not a certain measure of the condition of the gaseous mixture within the bottle. It is an object of this invention to provide a valve with means for cutting off the discharge of such gaseous material when the temperature inside the bottle is outside a desired range. For example, when the gaseous material is a common nitrogen/ethanol mixture, the valve is disabled at a temperature of about 35xc2x0 F. (1.7xc2x0 C.), or in any event, a temperature above the dew point of the mixture. As another example, when the gaseous material is oxygen being administered to a patient, it may be desirable to maintain the temperature of the oxygen within a fairly narrow range, which can be accomplished with a valve of this invention. Another source of possible heterogeneity when the gaseous material is a mixture, is in the filling process. In valves through which a mixture of gas and volatile liquid is both introduced to a bottle or tank and discharged from the bottle or tank, conventionally, the passages through which the gas mixture flows in filling and discharging are the same. When the whole or a part of these passages is restricted, and the pressure drop over the restricted passage during the filling process is great, the expansion of the gas as it leaves the restricted passage can so cool the mixture as to cause the volatile liquid to drop out of the mixture (outgas). In addition, the restriction drastically slows the filling process. Accordingly, it is a further object of this invention to provide a valve that permits faster filling and minimizes the danger of precipitating a volatile liquid component from a gaseous mixture during the filling process.
In accordance with this invention, generally stated, a bottle charged with a gaseous material intended to be discharged through a range of temperatures but not outside that range, is equipped with a valve through which the gaseous material is to be directed. The valve has a part wholly inside the bottle, the part having a restricted port through it through which the gaseous material passes to issue from the valve, and a thermally responsive member adapted to block the port when the temperature of the gaseous material is outside the predetermined range. The valve also has a fill port of greater diameter than the restricted discharge port, which permits faster filling with less danger of precipitating volatile liquids from a volatile liquid/gas mixture.